Pattern recognition is definitely an important component of fluid intelligence, but there are several others. Fluid intelligence varies depending on the neural structure of the brain. The brains of highly intelligent people are typically found to have a lower neurite density allowing for a faster and more efficient transmission of information. Such brains also show less cortical activity and lower consumption of glucose during the reasoning process. This greater neural efficiency enables the brain to access more information faster and hold it in working memory long enough to see patterns and make connections.
This means that pattern recognition, problem solving and verbal comprehension are all derivatives of mental speed and short-term memory (sometimes called “working memory capacity,” ) that are determined by the brain’s architecture.
So the short answer to your question is: pattern recognition is one of several cognitive abilities, including problem solving, verbal comprehension, concept acquisition, and others that are determined by the brain’s neural efficiency and working memory capacity.